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The OpenStack Install and Deploy Manual for Essex seems to imply that the whole stack can be deployed on one machine without the need for VMs. In fact, DevStack does exactly this.

However, the Openstack Basic Install for Folsom says "You need at least three machines (virtual or physical) with Ubuntu 12.04 (LTS) installed."

Is this something that has changed in the architecture? DevStack doesn't seem to have any problems running on a single machine, so why would a "proper" install of OpenStack? As I understand it, all the components are separately-running non-conflicting processes. The only thing that I can see being a problem is the potential for networking conflicts.

Are there things to watch out for by running it on a single machine?

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Maybe I'm asking the question wrongly. I'm not interested in DevStack because it's only for development and testing. It wipes data and other things that devs do. I don't want that. I was merely pointing out that DevStack demonstrates it as possible. I want a single machine install so that I can run OpenStack permanently, move my existing machines to VMs, and then reclaim the hardware by installing Compute Nodes on the original machines. A DevStack-like script would be great, but the existing DevStack script wipes data so it doesn't apply. – tudor Jan 8 '13 at 6:23
up vote 2 down vote accepted

Yes you can install Folsom and get everything running on a single machine (I just did it in my test lab). This isn't recommended for production since it gives you an "eggs all in one basket" scenario, but there isn't anything inherent in any of the components that would prevent you from doing this.

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What network configuration did you use for the Network Node? Did you use the same IP for the App and Public interfaces? – tudor Jan 13 '13 at 4:29
My test machine has 2 network cards so I just used separate interfaces. – tparker Jan 17 '13 at 15:37
So have you deploy that in production ? – Rahul Patil Aug 16 '13 at 13:47

The install manuals are intended to describe production-style deployments, where it doesn't make sense to do single-node installs; that's why the docs specify multiple machines.

You can still use DevStack to deploy everything on one machine for development/testing purposes.

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Yes, but DevStack makes assumptions to do with deployment like wiping data which a single-node install wouldn't do. – tudor Jan 8 '13 at 4:05

I'm looking at a similar scenario myself (a cluster of 3 nodes, 1 controller+2compute, on one site and a single machine on another site for DR and optimization of bandwidth); I'm so far had troubles following the guide (and I followed it to the letter). What worked for me it's the puppet modules deployment in which you can also specify a single node or a controller+compute installation by changing the certname:

puppet apply /etc/puppet/modules/openstack/examples/site.pp --certname openstack_all

for single node and

puppet apply /etc/puppet/modules/openstack/examples/site.pp --certname openstack_controller
puppet apply /etc/puppet/modules/openstack/examples/site.pp --certname openstack_computeX

for multi node. If you change configuration in the module and reapply it will update the config files with the modified settings.

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If you're interested in installing DevStack from stable branches you can do

git clone -b stable/folsom devstack/


git clone -b stable/essex devstack/
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I'm not interested in DevStack at all. I'm asking why DevStack installs on a single machine while the Folsom documentation says that 3 machines are a minimum requirement. – tudor Jan 8 '13 at 6:28

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